Roller mills for grinding solid material such as cement raw materials are known, for example from U.S. Pat. No. 4,828,189. This known mill is a so-called vertical roller mill and comprises a casing or mill body with a horizontal grinding table mounted for rotation about a vertical axis positioned within the mill body. Drive means such as a motor and a gear reducer, situated beneath the grinding table, are provided for rotating the grinding table.
Material is fed into the roller mill via a feed chute, which is typically positioned co-axially with and at a distance above the grinding table. When utilizing conventional prior art feed chutes there can be sticking problems with certain feed materials which can result in build up and plugging within the chute. To overcome this, the chute angle into the mill is typically increased toward the vertical which can be problematic because this results in increasing the height of feeding equipment and conveyors. With such a solution the velocity of the material hitting the table can also be a concern. In another solution, ports opening into the feed chute can be employed to mechanically clear plugs. However, this method can only be employed when the mill is shut down.